Stock Photo - The lake Hovsgol, or Khovsgol, in Mongolia. The lake Hovsgol is located in a montainous region, at the north_west of Mongolia, near the Russian frontiers, at 1645 m of altitude. It is 136 km long and 36.5 km wide. It is the deepest lake in Mongolia, and the second lake of the country by its superface. It is sustained by 96 streams, but only one river outflows it, the Egiin Gol, that connects it to the Baikal lake, in Russia, through the intermediary of the river Selenge. The lake Hovsgol is one of the most ancient lakes in the world. Its water, very pure, constitues an important reserve of freshwater on a world scale. The lake and its suroundings are protected by a national park Lake Hovsgol National Park.